The warm air from the Equator mixes with the cold air to the North....one direction.
The warm air from the Equator mixes with the cold air to the South...the other direction.
Hence, OPPOSITE directions.
Opposite spirals.
Rottingman's (and the mainstream's) explanation makes less sense for the simple fact that hurricanes wouldn't tend to be "seasonal" if it was caused by the Earth supposedly spinning. If that were the case, they'd occur more often year round.
Where do you get your info from? There are more places in the world than N. America.
- Atlantic Hurricane Season officially begins on June 1st and ends on November 30th each year. 97% of all tropical cyclones in the Atlantic fall within this period of time. The month most likely to have a hurricane is September.
- Northeast Pacific Hurricane Season begins on May 15th and ends on November 30th each year.
- Northwest Pacific Typhoon Season has no official start or end date since storms commonly occur all year long.
- The North Indian Cyclone Season begins in April and lasts until June. There is typically another heightened period of activity from late September to early December.
Worldwide, tropical cyclone activity peaks in late summer, when the difference between temperatures aloft and sea surface temperatures is the greatest. However, each particular basin has its own seasonal patterns. On a worldwide scale, May is the least active month, while September is the most active. It has more to do with the temperature of the water than it does the heat of the sun on a given day.
Water temperate caused by the sun is a factor in tropical storm development but it is not the only factor. While six factors appear to be necessary, tropical cyclones may occasionally form without meeting all of the following conditions:
- In most situations, water temperatures of at least 79.7 °F are needed down to a depth of at least 50 m (160 ft), waters of this temperature cause the overlying atmosphere to be unstable enough to sustain convection and thunderstorms.
- Another factor is rapid cooling with height, which allows the release of the heat of condensation that powers a tropical cyclone.
- High humidity is needed, especially in the lower-to-mid troposphere; when there is a great deal of moisture in the atmosphere, conditions are more favorable for disturbances to develop.
- Low amounts of wind shear are needed, as high shear is disruptive to the storm's circulation.
- Tropical cyclones generally need to form more than 345 mi (or five degrees of latitude) away from the equator, allowing the Coriolis effect to deflect winds blowing towards the low pressure center and creating a circulation. Because the Coriolis effect initiates and maintains their rotation, tropical cyclones rarely form or move within 5 degrees of the equator, where the effect is weakest.
- Lastly, a formative tropical cyclone needs a pre-existing system of disturbed weather. Tropical cyclones will not form spontaneously.
From wikipedia regarding Coriolis:
"The Earth's rotation imparts an acceleration known as the Coriolis effect, Coriolis acceleration, or colloquially, Coriolis force. This acceleration causes cyclonic systems to turn towards the poles in the absence of strong steering currents. The poleward portion of a tropical cyclone contains easterly winds, and the Coriolis effect pulls them slightly more poleward. The westerly winds on the equatorward portion of the cyclone pull slightly towards the equator, but, because the Coriolis effect weakens toward the equator, the net drag on the cyclone is poleward. Thus, tropical cyclones in the Northern Hemisphere usually turn north (before being blown east), and tropical cyclones in the Southern Hemisphere usually turn south (before being blown east) when no other effects counteract the Coriolis effect."So yes... it is about the sun's heat, or rather the accumulation of heat by the end of summer combined with the colder temperatures aloft creating this inversion. Hurricanes are dependent on that but they are also dependent on Coriolis and it is the Coriolis that gives them their rotation. Not the sun.